Risk for and temporal trends in cesarean surgical complications

It is possible that in the setting of increasing patient comorbidity and obesity, risk for surgical injury and need for reoperation is increasing. It is also possible that with differential uptake of evidence-based recommendations and increasing prevalence of risk factors such as obesity, risk for surgical site complications is increasing. The objective of this study was to evaluate trends in, risk factors for, and racial disparities related to cesarean complications.

This repeated cross-sectional study evaluated cesarean deliveries in the 2002-2014 National Inpatient Sample for women age 15-54. The primary outcome was a cesarean surgical complication composite including (i) surgical injuries, (ii) reoperation, and (iii) surgical site complications. Surgical injuries, reoperation, and surgical site complications were additionally evaluated individually as outcomes. Univariable and multivariable log linear regression models including demographic, clinical, and hospital factors were performed to assess risk for outcomes with unadjusted and adjusted risk ratios (aRR) with 95% confidence intervals (CI) as measures of association. Temporal trends were estimated using average annual percentage change from a joinpoint regression model. A stratified analysis was performed restricted to non-Hispanic black women. Data was weighted to provide national estimates.

A total of 16.2 million estimated cesarean deliveries (3.2 million unweighted cesarean deliveries) from 2002 to 2014 were included in this analysis. The prevalence of the cesarean surgical complication composite was 1.14%, surgical site complications occurred in 0.60%, surgical injuries in 0.49%, and reoperations in 0.10%. Comparing the end of the study (2012-2014) to the beginning of the study (2002-2003), adjusted risk for the composite was similar (aRR 0.93, 95% CI 0.92, 0.95). In comparison, surgical site complication risk was lower at the end of the study (aRR 0.77, 95% CI 0.75, 0.79) while risks for surgical injury (aRR 1.18, 95% CI 1.15, 1.22) and reoperation (1.18, 95% CI 1.10, 1.26) were higher. Non-Hispanic black women were at increased risk for surgical site complications (aRR 1.83, 95% CI 1.80, 1.87) and reoperation (aRR 1.44, 95% CI 1.37, 1.51), but not surgical injury (aRR 0.99, 95% CI 0.97, 1.02). In analyses stratified for non-Hispanic black women, there was a reduction in risk for surgical site complications at the end of the study period compared to the beginning similar to the primary analysis (aRR 0.76, 95% 0.72, 0.81) with a modest decrease in overall risk for the composite outcome (aRR 0.85, 95% CI 0.81, 0.89).

A decrease in risk for surgical site complications was offset by slightly increased risk for surgical injury and reoperation in adjusted analyses. Among non-Hispanic black women, surgical site complication risk decreased proportionately with this group still at significantly higher overall risk.